6533b826fe1ef96bd12834a9

RESEARCH PRODUCT

Intense magmatic degassing through the lake of Copahue volcano, 2013–2014

Tamburello G.[1]Agusto M.[2]Caselli A.[2]Tassi F.[34]Vaselli O.[34]Calabrese S.[1]Rouwet D.[5]Capaccioni B.[6]Di Napoli R.[1]Cardellini C.[7]Chiodini G.[5]Bitetto M.[1]Brusca L.[8]Bellomo S.[8]Aiuppa A.[18]

subject

Atmospheric Science010504 meteorology & atmospheric sciencesEarth scienceGeochemistrySoil ScienceAquatic ScienceOceanography010502 geochemistry & geophysics01 natural sciencesCiencias de la Tierra y relacionadas con el Medio AmbienteAtmosphereVulcanologíaFlux (metallurgy)Impact craterGeochemistry and PetrologyCrater lakeEarth and Planetary Sciences (miscellaneous)COPAHUECopahue volcanic lake degassingGeophysicCiencias Exactas y NaturalesChemical compositionWater Science and Technology0105 earth and related environmental sciencesvolcanic lakegeographyMagmatic gasesgeography.geographical_feature_categoryEcologyCopahuePaleontologydegassingForestryFumarolePlumeDEGASSINGGeophysicsVolcano13. Climate actionSpace and Planetary ScienceEarth-Surface ProcesseCopahue volcanovolatile flux from crater lakeCIENCIAS NATURALES Y EXACTASGeologyVOLCANIC LAKE

description

Here we report on the first assessment of volatile fluxes from the hyperacid crater lake hosted within the summit crater of Copahue, a very active volcano on the Argentina-Chile border. Our observations were performed using a variety of in situ and remote sensing techniques during field campaigns in March 2013, when the crater hosted an active fumarole field, and in March 2014, when an acidic volcanic lake covered the fumarole field. In the latter campaign, we found that 566 to 1373 t d -1 of SO 2 were being emitted from the lake in a plume that appeared largely invisible. This, combined with our derived bulk plume composition, was converted into flux of other volcanic species (H 2 O ~ 10989 t d -1 , CO 2 ~ 638 t d -1 , HCl ~ 66 t d -1 , H 2 ~ 3.3 t d -1 , and HBr ~ 0.05 t d -1 ). These levels of degassing, comparable to those seen at many open-vent degassing arc volcanoes, were surprisingly high for a volcano hosting a crater lake. Copahue's unusual degassing regime was also confirmed by the chemical composition of the plume that, although issuing from a hot (65°C) lake, preserves a close-to-magmatic signature. EQ3/6 models of gas-water-rock interaction in the lake were able to match observed compositions and demonstrated that magmatic gases emitted to the atmosphere were virtually unaffected by scrubbing of soluble (S and Cl) species. Finally, the derived large H 2 O flux (10,988 t d -1 ) suggested a mechanism in which magmatic gas stripping drove enhanced lake water evaporation, a process likely common to many degassing volcanic lakes worldwide. Key Points First volatile flux record of crater lake gas emissions from Copahue volcano Magmatic gases breaching through the lake surface Magmatic gas stripping drive enhanced lake water evaporation Fil: Tamburello, G.. Università degli Studi di Palermo; Italia Fil: Caselli, Alberto Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Tassi, F.. Università degli Studi di Firenze; Italia Fil: Vaselli, O.. Università degli Studi di Firenze; Italia Fil: Calabrese, S.. Università degli Studi di Palermo; Italia Fil: Rouwet, D.. Istituto Nazionale di Geofisica e Vulcanologia; Italia Fil: Capaccioni, B.. Universidad de Bologna; Italia Fil: Di Napoli, R.. Università degli Studi di Palermo; Italia Fil: Cardellini, C.. Università di Perugia; Italia Fil: Chiodini, G.. Istituto Nazionale di Geofisica e Vulcanologia; Italia Fil: Bitetto, M.. Università degli Studi di Palermo; Italia Fil: Brusca, L.. Istituto Nazionale Geofisica e Vulcanologia; Italia Fil: Bellomo, S.. Istituto Nazionale Geofisica e Vulcanologia; Italia Fil: Aiuppa, A.. Istituto Nazionale Geofisica e Vulcanologia; Italia

yearjournalcountryeditionlanguage
2015-09-01Journal of Geophysical Research: Solid Earth
https://doi.org/10.1002/2015jb012160